Liquid and gaseous fuel supply system



Feb. 925- 1,525,698 STOKES LIQUID AND GASEOUS FUEL SUPPLY SYSTEM Filed Dec.- 20.. 1921 7 I h an; v [a l/ INVENTQR.

- I Patented Feb. 10, 1925.

CHARLES LAWRENCE STOKES, 013' LOS ANGELES, CALIFORNIA.

LIQUID AND GASEO'US FUEL SUPPLY SYSTEM.

Application filed December 20, 1921. Serial No. 523,648.

To all whom it may concern:

Be it known that I, CHARLES LAWRENCE STOKES, a citizen of the United States, and resident of Los Angeles, in the county of Los Angeles and State of California, have invented certain new and useful Improvements in Liquid and Gaseous Fuel Supply Systems, of which the following is a specification.

i M invention relates to improvements in feeding fuel, both liquid and gaseous, to an internal combustion engine through means whereby a continuous supply of liquid and gaseous fuel is effected.

It is an object of my invention to extract the vapors of light fractions from hydrocarbon oils, especially gasoline, which is being fed to an internal combustion engine and to feed the heavier fractions after the extraction of light fractions therefrom also to the engine, whereby improved operation of the engine results, not only from a mechanical standpoint but also from the standpoint of economy.

July 29, 1919, I describe and claim a pioneer method of lifting liquid fuel from a lower to a higher level, utilizingthe vacuum induced by an internal combustion engine, the

liquid fuel being lightened by a small quantity of air and the air being carburetted thereby is drawn continuously into the engine manifold and consumed as part of the engine charge. This action is continuous and in my Patents Nos. 1,230,596, 1,230,537, 1,288,266, 1,303,610, 1,319,913, 1,302,725 and in my copending applications Serial Nos. 512,187 and 512,325, 1 have shown and de scribed different methods and means for utilizing carburetted air, apart from the liquid fuel.

In my present invention 1 now show and describe means for utilizing carburetted air, which is carburetted by the vapors of light fractions of hydrocarbon oils by addition to the main carburetted charge of the engine which is supplied through an engine carburetor, and 1 also show novel means for releasing the vapors of light fractions from hydrocarbon oils.

The description will be best understood by reference to the drawings in whicha Fir. 1, is a diagram, partly in section,

In my reissued Patent No. 14,701, dated which shows the application of my method as a whole.

Fig. 2 is a vertical section of a vacuum tank forming part; of the apparatus; F Fig. 3 is a section along the lines 33 of In the drawings the same numbers indicate like parts.

Fig. 2 illustrates a section of a vacuum tank, such as is well known in the art for supplying liquid fuel from a lower level to the carburetor of an engine at a higher level and Fig. 2 as a whole is termed a vacuum tank, such as resembles in general one which is made by the Stewart-Warner Speedometer Corporation, comprising a head 1 to which is attached a suction chamber 2 and a reservoir 3. Thehead 1 is usually a die casting and is provided with afit-ting 4: connected to a pipe 5 through which vacuum is applied to suction chamber 2. A fitting 6 is threadedin a central hole in head 1 and gives access to the interior of 2 through a small hole 7, being coupled to 4 by a union or other joint 8. A pipe 9 joins the suction chamber 2 to a source of fuel supply.. 10 and 11 are valves for alternately applying suction an atmosphere respectively to the interior of 2 and are operated by the rise and fall of a float 12 through the medium of levers 13, 1 1, 15 and 16, a sharp action being imparted to valves 10 and 11 through action of a kick spring 17, joined to the ends of levers 15 and 16. At the lower end of 2 is a passage 18 to which is connected to a flap valve 19 controlling the passage of liquid from suction chamber 2 into reservoir 3.

lnasmuch as the construction of the float and valves as above mentioned is well known in the art, and inasmuch as 1 do not herein claim any of the specific mechanism of the float and valve action it will not be necessary to enlarge upon the construction of the same beyond the general illustration embodying" the alternative application of vacuum and atmosphere to suction chamber 2. I Reservoir 3 is concentric with 2, and 1, 2 and 3 are rigidly fastened together with interposed gas ets to render the assembly air-tight, except as hereinafter described.

An annular space 20, between 2 and 3 is adapted to contain an air vent pipe 21 which has an enlarged portian 22 containing a will resistance wire 23, the ends of Which are connected to any suitable source of current supply (not shown). The lines AA represent a normal liquid level in' 2 and 3, for instance when just after a charge of liquid fuel has been drawn into 2 and partly discharged into 3. The lower end of air vent pipe 21 is brought well down below the liquid level AA and bent upwardly so that the upper outlet 24 is well above the liquid level A-A at all times. One or both of the branches of air vent pipe 22 may be perforated below liquid level A-A with one or more small holes 25, the purpose of which will be further described. A pipe 26 at the lower end of reservoir 3 carries fuel-from the vacuum tank to the carburetor 27 which is' attached to the intake manifold 28 of an internal combustion engine 29. 30 is the exhaust pipe of the engine, and suction pipe 5 is connected to manifold 28 at any convenient spot above the carburetor or the carburetor throttle (not shown), or in some cases it may be connected at or below the carburetor throttle.

A passage 40 in head 1 connects the interior of 2 through valve 11 with annular space 20, to the eifect that both 2 and 3 may be open to atmosphere through air vent pipe 21.

Air vent pipe 21 is wound around exhaust pipe 30 in a number of coils 3'1 and supply pipe 9 leads back to the main liquid fuel supply tank 32, which in the case of an automobile as illustrated is generally at the rear end of the car and at a lower level than the vacuum tank 3 or carburetor 27. Pipe 9 is fitted to tank 32 through a raised portion 33 which is normally above the liquid level in tank 32, and pipe 9 extends substantially to the-bottom of 32 and within the raised portion 33 pipe 9 is drilled with a small hole 34.

A filler cap 35 closes the filling opening of tank 32 and has attached thereto adip tube 36 of U shaped form which extends to the bottom of 32, having its outlet 37 above the normal liquid level therein and connecting to atmosphere through a vent 38 in cap 35.

At one or more points in one or both arms of 36 are placed small drill holes 39, the purpose of which will be further described.

The vacuum tank is mounted either on the exhaust manifold 30 or intake manifold 28, but as is the common custom it is close to the engine and generally placed under the hood of an automobile, and is placed at a higher level than the main supply tank 32 and the carburetor 27.

The operation is as follows:

Engine 29 being cran'ked, suction is thereby applied to manifold 28 and therefrom passes through pipe 5 to the interior of 7. It is to be noted that valve 10 intermit-.

tently increases the volume of suction applied to 2 while the volume of suction applied through 7 is constant for any particular throttle opening.v Valve 10 being open, valve 11 will be shut and therefore vacuum applied through 7 and 10 will be diverted through pipe 9 to tank 32. At the same time under normal conditions tube 36 will be filled with liquid to a static level therein and upon the application of suction through pipe 9 and hole 34 to the interior of tank 32 the liquid in tube 36 will be ejected through 37 and air will be thereby admitted to the tank through-38, and a small quantity of liquid fuel will be continuously leaking in to the interior of tube 36 through holes 39 and will be continuously agitated and ejected through 37 thereby liberating vapors of light fractions of hydrocarbon oils in continuous quantities.

The air, together with the vapors of light fractions which pass-in through 37 are sufiicient to break any vacuum within tank 32, and hole 34 being of not such a size as to satisfy the vacuum induced through valve 10 and hole 7, liquid fuel and carburetted air will thereby be lifted through pipe 9 and discharged into the interior of 2.

Float 12 will continue to rise until it reaches a predetermined position when. through the action of spring 17 valve 10 will be closed and valve 11 opened. Valve 11 is a valve for the purpose of admitting atmosphere to the interior of 2 in excess of the amount of air or vapor which is continuously being drawn through 7, so that it may discharge liquid therefrom to reservoir 3 through pipe 18 and valve 19, and the atmosphere so admitted is supplied through pipe 21, ejecting the liquid through the out lot 24 and sweeping around the-outside of suction chamber 2, picking up vapors of light fractions from the liquid in 3 and the air and vapors then pass through passageway 40 to the interior of 2 responsive to vacuum induced through 7. The annular area around valve 11 being much greater than that of hole 7 it will be seen that pipe 21 and passage 40 are amply able to vent both suction chamber 2 and reservoir 3. Valve 10 being closed it will be seen that suction through pipe 5 is exerted continuously on the interior of 2 thereby drawing vapors of light fractions not only from the interior of 2 but also from the interior of 3 and through pipe 9 from the interior of 32. In this manner a continuous carburetted charge, independent of the charge of liquid fuel supplied through 27, is being fed to the engine. Pipe 21 is arranged and operates in a similar manner to pipe 36, so that the vapors of light fractions are liberated from ill the liquid fuel in 3, and even more readily than in tank 32 because 3 is attached to the engine and the liquid fuel therein is subjccted to the heat of the engine.

For the purpose of abstracting the vapors of light fractions under all conditions pipe 21 is wound around the exhaust pipe in a coil 31 and contains an enlarged portion 22 with a resistance wire 23 therein and in very cold weather when the vapor pressure of low fractions is a minimum it will be seen that by supplying an electric current to 23 whereby the same is highly heated,- that air passing the'same will be highly heated before meeting with and agitating fuel in 21 which leaks in through holes 25, whereby vapors of light fractions are readily released and conveyed to the engine. As soon as the engine warms up, whereby exhaust pipe 30 and coil 31 become hot, air passing through pipe 21 is heated and the supply of electric current to 23 may be discontinued.

Heat, agitation and vacuum are all aids to the speedy liberation of the vapors of light fractions from hydrocarbon oils and it will thus be seen that I have provided novel and useful means to utilize the same.

In ordinary devices for supplying liquid fuel to internal combustion enginm, the fractions of hydrocarbon oils boiling between 80- Fahrenheit and 140 Fahrenheit are generally lost, inasmuch as they escape to atmosphere through the air vents in the vacuum tank, main supply tank and carburetor float chamber, when the temperature by any means reaches their boiling points.

' ln particular this factor of heat has caused great trouble in obtaining correct adjustment through the carburetor metering valve, or needle valve, inasmuch as bubbles of gas are released when the fuel is being drawn through the metering valve giving irregular and uneconomical operation of the engine.

Again, the vapors of light fractions rising from the liquid fuel in a heated vacuum tank are entirely lost, inasmuch as theyl escape from the air vents of both the suction chamber and reservoir to atmosphere, and the same condition applies to the main liquid supply tank. 1

These vapors of light fractions are the most valuable fractions from a liquid fuel, inasmuch as they impart qualities to the vapors of heavier fractions without which it is impossible to operate internal combustion engines, in particular automobile engines.

My invention covers means to not only conserve these vapors, which would normally be lost, but also to liberate them automatically and at will whereby they ma be carried and mixed with the heavier ractions to form a properly blended combustible mixture for the engine.

The utilization of these vapors of light fractions by my means enables the engine to be quickly started by a dry gas, and when started enables the engine to run smoothly with maximum power because the carburetor may be adjusted much closer to meet running conditions'when only the heavier fractions of a liquid fuel are fed therethrough. At the same time the vapors of light fractions,'of which a large percentage are normally lost, are mixed with the properly metered heavy fractions whereby acceleration is quickly effected and a large economy of fuel results by the use of normally waste vapors.

It may readily.be perceived that by regulating the annular area around valve 11, by making the valve stem smaller or larger, and also by regulating the size of hole 34, which is normally the size of a #drill, that the vapors of light fractions may be continuously withdrawn from tank 32, no

matter whether liquid fuel be supplied through -9 or not, inasmuch as the onl condition to be met is that the area of ole 7 should be such that it is less than the combined areas of hole 34 and the annular space round valve 11, to the effect that sufficient air is admitted through 34 and valve 11 to vent suction chamber 2'and permit liquid fuel to be discharged therefrom to reservoir '3. It will also be seen that, when 10 is open and 11 closed,'the combined areas of hole 7 and the annular space around valve 10 will be greaterthan hole 34 and in this manner air, vapors and liquid fuel will be raised to suction chamber 2 through pipe 9. One or more holes may be placed in pipes 21, 36 or 41 and preferably I place one hole, about the size of a No. 75 drill near the bend in each, the object being to expose a line stream of liquid fuel to the action of the air, heated or not, sweeping past where by the vapors of light fractions may be carried off and the heavier liquid fractions ejected and returned to the main body of li uid in 3 or 32. do not limit myself to the sizes of holes enumerated, inasmuch as they may be varied to meet different conditions of lift, heat and types of carburetors, engines, or vacuum induction vacuum ofthe engine, inasmuch as while 1i uid fuel is discharged by gravity to the cai buretor float chamber from the reservoir, it is withdrawn from the carbu retor float chamber by en ine suction.

By priming the engine for starting with vapors of light fractions, flooding and crank case dilution is avoided, and high economy results from using these vapors continuously.

I claim:

1. In combination, a vacuum tank, a liquid fuel supply tank, an internal combustion engine to which fuel is fed by suc tion, constantly open means to withdraw gaseous fuel continuously from the vacuum tank and liquid fuel supply tank responsive to the engine suction and means to agitate liquid fuel in the vacuum tank.

2. In combination, a vacuum tank, a liquid fuel supply tank, an internal combustion engine to which fuel is fed by suction, means to withdraw carburetted air from said tanks and means to agitate liquid fuel in said tanks, both of said means being responsive to the engine suction.

3. In combination, a vacuum tank having a suction chamber and a reservoir, a liquid fuel supply tank, an internal combustion engine to which fuel is fed by suction. means to pass air through the liquid fuel in the supply tank whereby the air is carburetted, means to draw said carburetted air and liquid fuel to the suction chamber whereby the liquid fuel is discharged to the reservoir and the carburetted air is drawn into the engine, means to pass further air through the liquid fuel in the reservoir whereby said air is carburetted and drawn through the suction chamber into the engine, said first and second mentioned carburetted air forming a continuous stream, and means to feed liquid fuel to the engine.

4. In combination, a vacuum tank having a suction chamber and a reservoir, a valve controlled conduit placing the suction chamher and reservoir in communication, a liquid drawn through the conduit into the suction chamber into the engine, said first and second mentioned carburetted air forming a continuous stream, and means to feed liquid fuel to the engine.

5. In a vacuum feed system, an enclosed chamber for supplying liquid fuel by gravity, a U-shaped pipeextending through said ing through the pipe, whereby said heated air may entrain liquid fuel in passing through the pipe.

7. In combination, an internal combustion engine having an intake manifold, a carburetor for supplying liquid fuel to the manifold, a vacuum tank having a suction chamber and reservoir, va ve controlled means placing-the lower portion of the suction chamber in communication with the reservoir to permit liquid fuel in the suction chamber to flow by gravity into the reser-' voir, a passageway placing the upper portions of the reservoir and suction chamber in communication, a constantly open passageway connecting the upper portion of the suction chamber to the manifold, a by-pass for placing the interior of the suction chamber in communication with the last mentioned passageway. alternately opened and closed valves controlling the first mentioned passageway and said by-pass, means for actuating the last mentioned valves, a fuel supply tank having an air inlet, a con stantly open conduit connecting the supply tank to the suction chamber, and a perforated air inlet pipe for the reservoir of U- shape having its outlet end terminating above the liquid level in the reservoir.

. 8. A combination as claimed in claim 7 in which the air inlet of the supply tank is formed by a perforated U-shaped tube having its bend located in close proximity to the bottom of the supply tank.

Signed at Los Angeles. in the county of Los Angeles and State of California, this 12th day of December A. D. 1921.

CHARLES LAVVRENOE STOKES. 

